Cathode-ray oscillograph



NOV. 19, 1929. I A, MATTHIAS 1,736,456 n CATHODE RAY OS CILLOGRAPH Nov- 19, 1929. A. yMATTHIAS' 1,736,456

CATHODE RAY OSCILLOGRAPH Filed ApIlil lO, 1928 2 Sheets-Sheet 2 Patented Nov.` 19, 1929 amm' Harms,

PATENT, OFFICE F BERLIN -WILMERSDOBE GERMANY CATHODE-RAY OSCILLOGRAPE Application led April 10, 1828, Serial No. 288,994, and in Germany April' 18, 1927.

My invention is related to cathode ray'oscillographs for recording transient electrlcal phenomena.4

One object of m invention is to provide a cathode ray oscil ograph, in which the exchanging, inserting or removing of the hotcgraphic plates or films can be accomp ished wighout spoiling the vacuum in the cathode tu e.

Another object of m invention is to grovide a cathode ray osci lograph of the a ove described kind, 1n which the film can be moved on continuously, so as. to take a large number of photographs, and the exposed parts of the film can be extracted without the necessity of openin the apparatus.

Other objects an advantages will appear in the followin specification and the novel features ,of the invention will be particularly 20 pointed out in the a pended clalms.

My invention is i lustrated in the accompanying drawings, forming part of this application, in which Fig. 1 is a vertical section through the cathode ray oscillograph.v v

Fig. 2 is a plain view of the base of another form containing the recordlng apparatus, the cover being' removed.

Fig. 3 is a schematic diagram of another form of base. n

Fig. 4 is yet another des1gn of the base.

Fig. 5 is a section on the line A-B in- Fi 1. Fig.

Fig.; 1. 1g. 1. 1g. Fig. 2.

Fig. 9 1s a section on the l1ne I-K 1n Fig. 10 is a detailed sketch ofthe packing at the fastening screws for the base.

As regards Fig. 1, the apparatus illustrated consists of the cathode tube 1, in' the top of which the cathode 2 is arranged and 1n the bottom the anode 3. The cathode 2 1s connected with the h. t. side of a transformer via the bushin 4. The bottom of the cathode `tube is joine to the metal tube' 6, the top 6 is a section on the line C-D in 7 is a section on the line, E-F in 8 is a section on the line G-H in part of which is surrounded by a coil 7 servmg to concentrate the cathode rays enterv ing the cathode through the opening 5. Pairs of divertin plates 8 and 9 are provided in the meta tube 6. The diversion of the cathode rays is dependent on the alteration in the voltage and on time. ,The base 10 joins on the metal tube and contains the device for recording the alterations in thev electrical phenomena indicated by the movement of the ce stream of the 4cathode rays.

The base 10 has extensions 11 and 12 on` both sides. At the end of extension 11 is supported a drum 13, in which a spool 14 is provided. Two spools 15 andp16 are arran ed 65f 1n the extension 12 and are driven by an e ectric motor 18 over a worm caring 17. The extensions are providedwit narrow slits 19 and 20 running vparallel to the front side of l the base. These slitsterminate on the one side in the recording chamber 21 and on the other side lead into the drum 13 or between the spools 15 and 16. The film 48 to be exposed to the cathode ra s is wound on the spool 14 and conveyed t rough the slits 19 15 and 20 to the spools 15 and 16. These motordriven spools draw the film oi spool 14 through the recording chamber 21, in which the film is exposed to the cathode rays. Behind the spools 15 and,I 16, the film passes so into the film box 22 being dprovided 4with a door 56 which can be locke by a spring 55. Between the spools 15v and ,16 and the film box an externally operated knife 23 is ar-y ranged. i The cathode tube 1 the metal tube 6 and the Ahollow space 21 in the base 10 are highly evacuated. -The vacuum is produced and maintained by the highvacuum pump 41 and .the vacuum pumps 24 and 25. 'I'he narrow 90 slits 19 and 20 are ractically completely filled by the film, so t at ractically no air can find its way throught ese slits into the evacuated apparatus. In order to increase the air-tightness of the slits, their sides can be fitted with flexible lugs, which press against the edge of the film and thereby render the passage of air more diilicult. The longer the Vslits are, the better is of course, the packing.

In order to limit the output of the pumps for maintaining the vacuums, the drop of pressure between theouter air and recording space 'ymay be distributed by roviding extensions 26 in the slits, bein eit er connected to prevacuum stages of t e high vacuum pump,.or, as shown in the drawing, to special`prevacuum pumps 24 and 25 via the pressure equalizing spaces 27 and 28..

In general it will be easily possible to shove the beginning of the film out of the drum 13 into the slit 19 and on through the recording chamber 21 into the slit 20. Lugs 54 are rovided to facilitate guiding of the film. n view of the fact that in s ite ofall precautions sticking may occur, 1t is best to make the side wall 29 of the base piece, which closesthe slit on the side, detachable, in order to be able to readily guide the film into the slits and between the rollers'on removing the side wall. The side 4wall is fastened to the base and either it can a packing 31 of 4rub er can be inserted between the wall and base piece.

The slits 19 and 20, made according to the invention, are capable of maintaining the vacuum in'the recordin chamber, even if,

' as illustrated in Fig. 1, t e entrance .and egiit -l positions fforr the film are in connection with the external air, however itis advantageous to provide the cover 32 of the drum 13 with aground conical edge. By this means an ez.:- cessive 'ingress of air is avoided and 1t 1s ossiblelto stop the pumps for a time even uring service.y

' In Fig. 2 a design incorporating the invention is shown, in which the lm 43 is unwound from a spool 33 and wound on a spool 34. Both spools are arranged in the base 10 and the film passes through the narrow curved slits 35 andI 36 between them. The slits nare as in Fig. 1 provided with extensions 37, which are in connection with the vacuum pumps 38, 39, andA serve to distribute the pressure drop between the outerair and lthe recording chamber. The recording chamber 21 is evacuated by means of a high vacuum' pump via thetube 41. The film is moved by -means of the spool 34, driven by the motor 42 over the worm gearing 43.

In orderto avoid the difficulties encountered in maintaining the recording chamber airtight, one slit can be done away with and the 'film spool arranged directly in the recording chamber, asshown in Fig. 3.v The base 10 is lconvex at one side of the recording chamber,

21 and in the bulge 44 av film spool 45 is arranged. In an extension 46 on the opposite 'side of the base, the slit 20, its extension 26 connected with the vacuum pumps 24 and 25, as well as the spools 15 and 16, are-provided. The s ools driven by the motor 18 draw the film rom the drum 45 and convey it into the film box 22, out of which ,the exposed Iiece by'means of sc rews 30 e ground into position or` part of the yfilm can be taken, after it has een separated from the remaining part by the knife 23.

Fig. 4 shows a somewhat altered design, in which the slit 20 does not follow a straight path but is curved shaped foi' the purpose of increasing thev resistance to the passage of air. Although it is also possible to construct the slit with stationary walls, it is advantageous to replace one side of the vcurved parts by the spools 46 and 47, so that the film may slide more easily. One or both spools can be driven by the motor 48 over the worm gearing 49. The shaft of the toothed wheel 49 is provided at its end with lugs 57, which engage in slots 58 in the spool. Since the front side ofthe spools must be air-tight so as to preventl air entering the slit, the spools are appropriately supported in conical bearings as shown in Fig. 9.- The conical bearing surfaces 50 can be easily made air-tight by means of grease. As it is possible for the screws with which the detachable side wall is fastened to leak in the course of time, it is advisable to provide them with an additional packing as in Fig. 10. The detachable side wall 29 is thus designed so thateach screw hole 51 is surrounded with a circular shaped collar 52 having a ground outer surface. The ingress of air to the screw is prevented by a cap 53 mounted on the collar, the inner conical surface of the cap` being ground.

rom the above description it is clear that, with a cathode ray oscillogra h embodying my invention any number o photographs can be taken successively without opening the recording chamber and thereby disturbing the vacuum.l This advantage is of great importance especially in the study of atmospheric disturbances in h. t. conductors, since the cathode ray oscillograph is thus always read for service and can also record a large num er of disturbing waves occurring at short intervals. -Apart from this, it is naturally also important for laboratory measurements that by using a cathode ray oscillograph according to my invention the time at disposal can be fully utilized, as the preliminary work merely consists in inserting the film roll and evacuating the cathode tube only once for a large number of records.

Although I have described some embodiments of 'my invention, it will be obvious to those skilled in the art that various modifications may be made in the details of construction and in design and proportion of the several parts without departing from the principles herein set forth.

I claim as my invention:

1. In a cathode ray oscillogra h, in combination, a cathode tube, means or diverting the catho-de rays, means for the evacuation of the tube, a base piece on the end of the tube and openings in said base piece adapted 3. In a cathode ray oscillograph, in combination, a cathode tube, vacuum pumps connected with'said cathode tube, a base piece provided with openings adapted for the insertion and extraction of a bod covered with a layer which is sensitive to lig t, and a sucking tube connecting said base piece with said vacuum pum s. p

4. In a cat ode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube, means for the evacuation of said tube land said base piece,4 and narrow slits provided in opposite side walls of said base iece. i

5. n a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube, means for the evacuation of said tube and said base piece, and narrow slits running parallel to the front wall of the base piece, provided in opposite side walls of said base piece. p

6. In a cathode'ray oscillograph, .in combination, a cathode tube, a base piece at the end of the tube, means for the evacuation of said tube and said base piece, narrow slits running parallel to the front wall of the said base piece, provided in opposite side Walls of said base piece, said slits being continued/over, extenslons on both sides of the base piece, thus forming long narrow canals in them.

7. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube, means for the evacuation of said tube and said base piece, narrow slits runnin parallel to the front wall of the base piece, provided in opposite side walls of said base piece, said slits being continued over extensions on both sides of the base piece, thus forming lon narrow canals in '.them, one'of the side Wa ls of the base piece being` adapted to be removed.

8. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube, means for the evacuation of said tube and s aid basepiece, narrow slits running parallel to the front'wall of the base piece provided in opposite side walls of said base piece, said slits being continued over extensions on both sides of the base piece, thus forming 'long narrow canals in them and extensions in said canals with means for the evacuation of these extensions.

9. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube, long narrow canals provided withenlargements, extending over extensions of said base piece on both sides of the base piece, vacuum pumps connectedoto the record chamber in sald base piece and to the tube, said pumps having ressure equalizing spaces which are connected to said enlargements by sucking tubes;

10. In a cathode ray oscillograph, in comy bination, a cathode tube, a base piece on the end of the tube forming a record chamber, long narrow canals provided with enlargements, extending over extensions of said base piece on both sides of the base piece, lmeans for evacuating the cathode tube, the record chamber and the enlargements of the canals, one canal leading to a drum which contains a spool adapted to admit a ilm, the other canal leading between two spools adapted to be rotated.

'-11. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube forming a record chamber,

- narrow slits running parallel to the front wall of the record chamber provided in opposite side walls of said record chamber, said slits being continued in the base piece thus forming narrow curved canals each of them leadingto a spool being provided in the base piece, said spools being adapted to be rotated.

12. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube forming a record chamber, vacuum pumps connected to the tube and the record chamber, narrow canals leading from the record chamber to spools provided in the base piece, said canals having enlargements which are connected via pressure equalizing spaces to said vacuum pumps.

13. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube forming a-record chamber, means for the evacuation of the tube and the record chamber, a spool in the record chamber being adapted to admit a film, a narrow slit provided in the side wall of the record chamber, said slit being continued through an extension of the base piece, thus forming a long narrow canal which leads between two spools at the end of said extension, the spools being adapted to be rotated.

14. In a cathode ray oscillograph, in combination, a cathode tube, a base piece on the end of the tube forming a record chamber, vacuum pumps connected to the tube and the record chamber, a spool in the record chamber being adapted to admit a film, a long narrow canal leading from the record chamber through an extension of the base piece to two spools at the end of said extension, said canal `having enlargements which are connected via pressure equalizing spaces to said vacuum pumps.

15. In a cathode ray oscill'ograph, in combination, a cathode tube, a base piece on the end of the tube forming a record chamber,

' means for the evacuation of the tube and the record chamber, a spool in the record chamber being adapted to admit a film, a narrow 5 curved canal leading from the record chamber through the base piece to the external air and lugs in the record chamber walls, ada ted to guide the film from said spool to t e entrance of said canal.

16. In a cathode rayoscillograph, in combination, a cathode tube, a base piece on the end ofthe tube-forming a record chamber, vacuum pumps connected to the tube and theA recordl chamber, a spool in the record Amchamber vbeing adapted to admit a film, a

narrowcurved canal leading from the record chamber'.'through the base piece to the externalail'. enlargements 1n said canal being connected via pressure equalizing spaces go to said vacuum pumps.

v17.l In acathoderay oscillograph, in combination, a cathode tube, a base piece on the end of the tube forming a record chamber, vacuum pumps connected to the tube and g5 the record chamber, a spool inthe record chamber being adapted to admit a film, a narrow curved canal leading from the record chamber through the base piece to the external air, enlargements in said canal being connected via pressure equalizing spaces to said vacuum pumps, one side of the curved vparts of the canal being replaced by rolls which are adapted` to be rotated.

18. In a cathode ray oscillograph, in combination, a cathode ray tube, a base iece on the end of the tube formin a record c amber, means for the evacuation of the tube and the record chamber, a spool in the record chamber being adapted to admit a film, a narrow curved canal leading from the record chamber through the base piece to the' ex ternal air, one side of the curved arts of, the canal being vreplaced by rolls 'w ichare adapted to be rotated'and have conical bear-- ,45 ing surfaces.

19. In a cathode ray oscillograph, in ccmbination, a cathode tube,a base piecel on the end of the tube forming a ,recordchamben vacuum pumps connected to the tube and the record chamber, a spool in the record chamber being adapted to admit a film, a narrow curved canal leading froml the record chamber through the base piece to the external air, enlargements in said canal being connected via pressure equalizing spaces to said vacuum pumps, one side of the curved parts of the canals being replaced by rolls which y are adapted to be rotated and have conical bearing surfaces, one of the side walls of the base piece, covering the record chamber, the spool for the lm and the canal, being adapted to be removed. 4'

In testimony whereof I ailix my signature.

. .65 ADoLE MATTHIAS. 

